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Add new Java rule GCI82 - Make non reassigned variables constants
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‎CHANGELOG.md‎

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### Added
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- Add new Java rule GCI82 - Make non reassigned variables constants
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- update developers list + update maven plugins versions

‎RULES.md‎

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| GCI78 | Const parameter in batch update | Don't set const parameter in batch update => Put its in query. Creating this parameter and destroying it consumes CPU cycles and RAM unnecessarily. | | ✅ | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 |
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| GCI79 | Free resources | try-with-resources Statement needs to be implemented for any object that implements the AutoCloseable interface, it save computer resources. | | ✅ | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 |
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| GCI81 | Specify struct layouts | When possible, specify struct layouts to optimize their memory footprint | | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | ✅ | 🚫 |
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| GCI82 | Make variable constant | A variable is never reassigned and can be made constant | | 🚀 | 🚀 | 🚀 | 🚀 | 🚀 | ✅ | 🚫 |
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| GCI82 | Make variable constant | A variable is never reassigned and can be made constant | | ✅ | 🚀 | 🚀 | 🚀 | 🚀 | ✅ | 🚫 |
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| GCI83 | Replace Enum ToString() with nameof | When no string format is applied, use nameof instead of ToString() for performance | | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | ✅ | 🚫 |
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| GCI84 | Avoid async void methods | Use async Task methods instead, for performance, stability and testability | | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | ✅ | 🚫 |
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| GCI85 | Make type sealed | Seal types that don't need inheritance for performance reasons | | 🚫 | 🚫 | 🚫 | 🚫 | 🚫 | ✅ | 🚫 |

‎src/main/rules/GCI82/java/GCI82.asciidoc‎

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:!sectids:
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Variable can be made constant.
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== Why is this an issue ?
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Unlike variables, constant values are known at compile time and are injected as is in the code, requiring no runtime processing and therefore reducing the environmental footprint.
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Although good compilers will const eligible variables by themselves, it is still good practice to declare them constant, as it makes the code intent clearer.
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=== When can it be ignored ?
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This rule should not be ignored.
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== Non compliant examples
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[source, java]
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----
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public class MyClass {
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private final Logger logger = Logger.getLogger("");
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private Object myNonFinalAndNotReassignedObject = new Object(); // Noncompliant, object initialized but neither used nor reassigned
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private String varDefinedInClassNotReassigned = "0"; // Noncompliant, object initialized and used but not reassigned
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private String varDefinedInClassNotUsed = "0"; // Noncompliant, simple type object initialized but neither used nor reassigned
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void localVariableNotReassigned() {
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String y4 = "10"; // Noncompliant, local variable initialized but not reassigned
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logger.info(y4);
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logger.info(varDefinedInClassNotReassigned);
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}
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}
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----
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== Compliant examples
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[source, java]
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----
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public class MyClass {
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private final Logger logger = Logger.getLogger(""); // Compliant, object initialized and used (never reassigned but ok because "final" keyword used)
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private Object myNonFinalAndReassignedObject = new Object(); // Compliant, reassigned in method
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private final Object myFinalAndNotReassignedObject = new Object(); // Compliant, object initialized and never reassigned but 'final' keyword used
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private static final String CONSTANT = "toto"; // Compliant, because 'static' and 'final' keywords
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private String varDefinedInClassReassigned = "0"; // Compliant, reassigned in method
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private String varDefinedInConstructorReassigned = "1"; // Compliant, reassigned in constructor
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public MyClass() {
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varDefinedInConstructorReassigned = "3";
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logger.info(varDefinedInConstructorReassigned);
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}
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void localVariableReassigned() {
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String y1 = "10"; // Compliant, reassigned above
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final String PI = "3.14159"; // Compliant, not reassigned but 'final' keyword used
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y1 = "titi";
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logger.info(y1);
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logger.info(PI);
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}
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void localVariableIncrement() {
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String y2 = "10"; // Compliant, reassigned above
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y2 += "titi";
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logger.info(y2);
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}
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void localIntVariableIncrement() {
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int y3 = 10; // Compliant, reassigned above
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++y3;
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logger.info(y3+"");
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}
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void classVariableReassigned() {
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varDefinedInClassReassigned = "1";
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logger.info(varDefinedInClassReassigned);
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logger.info(varDefinedInClassNotReassigned);
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logger.info(CONSTANT);
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}
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void classVariableReassignedBis() {
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varDefinedInClassReassigned = "2"; // method to avoid sonarqube error asking for moving class variable "varDefinedInClassReassigned" to local variable method
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myNonFinalAndReassignedObject = new Object();
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logger.info(varDefinedInClassReassigned);
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logger.info(myNonFinalAndReassignedObject);
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logger.info(myFinalAndNotReassignedObject);
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}
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}
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----

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